1.1.1 Field of Invention
This invention relates generally to the field of providing medical care to ambulatory nonhospitalized patients, and more particularly to a novel system-- encompassing both apparatus and method--for monitoring the condition of people whose general physical condition is frail or unstable--but who are still able to live at home.
1.1.2 Prior Art
Historically, people in acute physical distress were visited in their homes by physicians who diagnosed medical problems with the aid of a few simple, crude instruments. With the advent of modern sophisticated diagnostic techniques and equipment, house calls were discontinued.
People in medical distress now must go to the physician's office or to a hospital emergency room for treatment. Adding insult to injury, the patient must often go to another facility such as a specialist's office or a testing laboratory, since the diagnostic equipment in most physicians' offices is insufficient for many diagnoses, especially of cardiovascular malfunctions.
Thus the patient while already ill--and often partly incapacitated--must travel repeatedly and sometimes on short notice to several health-care professionals. Not only does this frequently entail great effort, discomfort and cost, but in addition the stress of these efforts often accelerates the decline of the patient's health, further increasing the cost of medical care.
Furthermore, these circumstances place an unacceptable financial burden on most patients and on the government agencies that underwrite the cost of many patients' health care.
Although many of the patients who are adversely affected by these circumstances are elderly, I wish to emphasize that both the problem area and the population "group" addressed by my invention sweep far more broadly than ministering to the health-services needs of the elderly.
To the contrary, the problems outlined above are of crucial importance to many young and middle-aged people who are part of the general population. These segments of the population are normally expected to be active in wage-earning or family management, but their health problems interfere with those roles. Since they are not at retirement age and often have neither social-security benefits nor savings, these people may from some perspectives be "harder hit" by disabling or semidisabling illness than are the elderly.
Certain prior patents may be worthy of mention in this connection and will be discussed briefly below--particularly U.S. Pat. No. 4,296,756 and certain patents cited in the prosecution of the corresponding patent application.
From these patents it can be seen that adequate technology is at hand for automated remote monitoring of any one of several different health-related parameters considered individually. Further, technology is at hand for automated remote monitoring of certain closely related groupings of more than one health-related parameter, where such groupings have been chosen by prior artisans as going to a particular malady of concern.
It can be appreciated from a study of these patents that each of the innovations disclosed in them is potentially a very useful and valuable advance. It can further be appreciated from a review of these patents, however, that they are not addressed to, and do not solve, the problems enumerated above.
The reason is threefold. First, the inventions presented in each of these patents, and also in all of them considered together, are directed to particular relatively narrow areas of medical concern.
Second, most of these inventions involve at least semiactive participation by the patient--stepwise maneuvers or behavior in response to specific instructions from an operator. It will be understood that such a mode of operation places a requirement on the mental organization and sometimes physical capability of the patient, and also places an additional requirement on the time and attentiveness of the operator. This latter point is especially important when there is no operator or aide at the patient's location.
Third, the inventions presented in each of these patents are disclosed almost exclusively to diagnosis, tacitly assuming that proper follow-up measures somehow will be provided outside the scope of the invention itself, and on an ad hoc basis--and these inventions thus lack a component of systematic response to diagnosis that is crucially important.
Therefore as will be seen, these patents fail to address the broad social and technological problem introduced above. This problem arises from the unavailability of house calls to the enormous general population of people who live at home and who are either sick or prospectively sick.
Their sicknesses or prospective sicknesses do not fall into any single convenient category, or even into any specific grouping of categories by relevant parameter. They require not only regular systematic diagnosis, but furthermore a response that is integrally associated with and routinely provided with the diagnosis.
U.S. Pat. No. 4,296,756 issued on Oct. 27, 1981 to Dunning and Enright for a "Remote Pulmonary Function Tester." It describes a remote pulmonary-function tester which interfaces to a central computer through telephone lines for review by an operator. This patent is limited to pulmonary testing--that is, to assessing the condition of the patient's lungs and the likely causes of any abnormalities detected.
Also serving as examples of inventions focusing on pulmonary function are U.S. Pat. Nos. 3,726,270 to Griffis et al., 3,896,792 to Vail et al., 3,977,394 to Jones et al., and 4,034,743 to Greenwood et al. Griffis' system transmits pulmonary data to a central location in real time to a central location, where the data "may be studied" by a "specialist." Vail's device does likewise, and it is commented that "such data can be evaluated with an eye toward earlier detection of disease and more effective treatment thereof . . . "
Jones provides a "computerized pulmonary analyzer" in which data from four pulmonary tests are automatically evaluated. As in most of the other inventions here under discussion, the "operator tells the test subject which breaathing maneuver he must follow for a desired test." It can be readily appreciated that such a procedure relies heavily on the patient's intelligent and active cooperation, and yields very questionable results when the operator cannot actually see the patient.
Greenwood seeks to provide "fully automated pulmonary function testing apparatus requiring relatively low levels of operator skill," but again at various points in the multifunction test procedure "the patient is asked . . . to breathe in a predetermined manner". For example, in one test the patient is expected to breathe "with maximal effort" against an obstruction; in another, "a patient inspires a full breath of pure oxygen and then expires at a substantially constant rate." Later the patient is told "to increase the rate of expiration" --and so forth.
Also among references cited in the prosecution of the Dunning application were U.S. Pat. Nos. 3,886,314 to Pori, 3,819,863 to Slaght, and 4,129,125 to Lester et al. The first of these relates exclusively to improvements in an eight-channel telemetering system for electroencephalographic data. The thrust of the invention is to facilitate communication between a remote data-system operator and "the resident doctor who is . . . applying electrodes from an EEG unit to the patient's head." From this it may be seen how far from a broad surveillance system Pori's device is, and how much individual on-site attention it demands.
Slaght's invention relates almost exclusively to electrocardiographic data. He introduces "a data transmitting terminal, primarily designed and intended for the coding of information relating to a patent, and of an electrocardiogram relating to that patient, for transmission via a communication line or link to a remote computer."
There are some systems that take one step in the direction of broader comprehensive screening, but it is a small step. Generally these systems collect plural-parameter data related to a particular malady as distinct from a particular organ. An example is the Lester patent, which focuses on crib death in infants. The invention is "an electronic monitoring device particularly suitable for babies," and that continuously monitors heart-beat rhythm, breathing rhythm, and temperature.
Lester's device "is preferably in the form of a belt having a buckle which houses the computer and memory. The unit is turned on by closing the belt into the buckle around the body of the patient. Should any of the patient's vital signs become abnormal, the electronic device . . . will sound the alarm alerting personnel near the patient that a failure has taken place. This will give persons near the patient ample opportunity to act on the patient in an attempt to restore breathing or other vital signs."
These excerpts from the Lester patent will be sufficient to show that the invention is (1) simply an acute-condition alarm system. That system is (2) limited to detecting vital signs, indeed a small number of such signs, and particularly to a highly simplified assessment of these few signs as against threshold criteria.
The excerpts also validate the earlier comments to the effect that the prior art is (3) narrowly focused on a particular medical problem, and (4) subject to a generalized assumption of suitable therapeutic response from "persons near the patient". In the broader problem area that is the target of my invention, it is to be generally assumed that there are no such persons.
Medical monitoring is a large field. To review here in detail a full cross-section of this field would be impractical, but in the preceding paragraphs I have discussed the prior art which appears to me most relevant to my invention.